FAIRWAY, KS (KCTV) -- It rained and thundered earlier on Wednesday but really when it comes to rain, we are just getting started. Over the next three days there is a chance, if the weather pattern remains locked in place, that Kansas City and surrounding areas could pick up as much as six inches of rain. And you can blame it on an anti-cyclone. What’s an anti-cyclone, you ask? Simple, it’s the opposite of a cyclone. A cyclone is a large weather system consisting of low pressure or counter-clockwise winds. So an anti-cyclone would be the opposite. A large high pressure area with clockwise winds. The large high pressure area bringing us our rainy pattern on Wednesday was sitting near the New Mexico/Arizona border.
Note the gold arrows pointing in a clockwise direction around the high pressure area. But the high isn’t creating the thunderstorms. Most of the time, fair weather and clear skies are associated with high pressure areas. So what’s causing all the rain and thunder. Waves of energy are helping to initiate thunderstorms that move around the periphery of the expansive high and if you follow the arrows you will see the arrows pass near Kansas City. Do you also see the second set of arrows? That’s the northern branch of the jet stream which is helping to orient the thunderstorms in a north-south direction. As long as this upper level feature stays put, then we could have thunderstorms rolling over the same areas and that could lead to flash flooding. For instance, a thunderstorm complex is expected to develop late tonight and continue through the first half of the day Thursday.
See how the rain appears to flow from Omaha toward Springfield, Missouri. This is because of the upper level high out west and the jet stream flowing north to south just to our east. After a lull Thursday afternoon, another thunderstorm complex is expected to develop northwest of Kansas City Thursday night and settle in for a long-lasting rain for most of the day on Friday.
Notice again how these thunderstorms appear to be running along a line from Omaha to near Springfield. When areas of thunderstorms roll over the same area again and again, it’s referred to as a training effect and can lead to serious flash flooding. And we must watch Friday morning’s thunderstorms carefully because this time the thunderstorms may shift a little farther west because the anti-cyclone weakens and shifts slightly farther west. That would keep Kansas City in the heart of the heaviest bands of rain. That’s why the below map has such a large area of rainfall totals that could range from three to as much as six inches by Friday night.
We needed the rain as it was starting to get dry in some parts of the region. A recent drought monitor showed abnormally dry conditions developing across northern Missouri. That’ll change between now and the weekend and we’re just getting started.